Mandarin tangerine called Nadorcott

ABSTRACT

A new variety of Mandarin Tangerine called `Nadorcott` is distinguished by its seedless fruit under self-pollination conditions. The fruit is easy peeling with a superior rind and juice color when compared to `Murcott.` The fruit has excellent aroma and flavor, ease of segment separation, tender segment skin and is mid-season maturing with a highly productive yield even for young trees.

DESCRIPTION Field of the Invention

This application is being filed pursuant to the provisions of theInternational Union for the Protection of New Varieties of Plants(U.P.O.V.).

This invention comprises a novel variety of Mandarin Tangerine tree(Citrus reticulata Blanco) presently named `Nadorcott` which isprimarily characterized by its seedless and easy peeling fruit and byits attractive orange red rind color.

BACKGROUND AND ASEXUAL REPRODUCTION OF THE NEW VARIETY

In 1982, the inventor observed a variety of Mandarin among 18 year old`Murcott` trees planted in 1964 in a nucellar selection program plot inINRA experiment station near Afourer town. The selection, assignedexperimental code `Inra W,` is believed to be the result of a chancecross-pollination between the `Murcott` Mandarin as a seed bearingparent and an unknown pollen parent.

Budwood of `Inra W` was asexually propagated on a small scale forexperimental purposes at the Sasma Nursery in Menasra at the region ofKenitra. Later and in early 1983, experimental plots of 2 to 4 hectareswere also established at Kedima and Mokala near Taroudant in the SoussValley, southwest of Morocco and also in a plot near Marrakech City. In1985, the young trees bore fruit of the same characteristics as thoseproduced by the original tree, namely, fruit with a superior rind colorwhich was orange red as distinguished from the yellowish orange of the`Murcott` fruit. However, `Inra W` was rejected as a commercial varietybecause of its high seed content.

In the spring of 1988, the inventor observed five-year old trees of`Inra W` planted under the `Murcott Sasma` name on a farm belonging tothe Domaines Agricoles Company in Rabat. Those trees were renamed`Afourer` and the inventor noticed that while some yellowish greenfruits of these trees, which resulted from out of season blooming, wereseedless, the red orange fruits were very seedy. This is the discoveryof the present invention. Experiments were conducted to betterunderstand the seedless phenomenon. Accordingly, two five-year old treesof `Afourer` were covered by an insect proof screen before the nextflowering period. The covered trees produced complete seedless fruitwhile all the fruit produced by the non-covered trees were highly seedy.

In 1990-1991, an experimental orchard was established in a locationremote from other citrus trees 30 kilometers from Marrakech City whereno citrus was located. At this orchard, it was verified that the newvariety is seedless only if cross-pollination is prevented. An averageof only 0.2 to 0.5 seed per fruit was found in a sample of 3,000 fruits.

The trees of the orchard near Marrakech were asexually reproduced bygrafting budwood onto sour orange rootstock. The result was a varietywhich is highly homogenous, genetically stable and highly reproductiveat an early age. For example, 15 metric tons of fruit per hectare atthree years after planting and 30 metric tons of fruit per hectare afterfour years of planting were produced.

The new variety, called `Nadorcott`, matures by mid-December and harveststarts in January and ends by late March.

Two other experimental orchards were established in 1991 and 1992 inBeni Mellal and also in the area north of Rabat. The orchard at BeniMellal was discarded because its distance from other citrus groves wasinsufficient to prevent cross-pollination from other citrus varieties.The experimental farm north of Rabat has been maintained.

Two rootstock trials were carried out in the Taroudant and Marrakechareas in 1992 and 1993. The trials included the rootstock of `SourOrange,` `Cleopatra Mandarin,` `Troyer Citrange,` `Citrus Volkameriana,``Rangpur Lime,` `Rough Lemon,` `Orlando Tangelo` and `CitrumeloSacaton.` Preliminary results indicate that the essentialcharacteristics of `Nadorcott` are not affected by the listedrootstocks. When budded on `Troyer Citrange,` there was no abnormalityor bud union crease.

Studies of hand cross-pollination were made between `Nadorcott`, andother seedy and seedless varieties. For each combination, `Nadorcott`was used as a female parent and as a pollinator. The studies show thatwhen self-pollinated, `Nadorcott` is seedless while the parent variety,`Murcott,` is seedy. The average number of seeds per fruit when`Nadorcott` was used as a pollinator or as a seed bearing parent rangedfrom 5 to 35 depending on the combination.

DESCRIPTION OF THE DRAWINGS

FIG. 1: The original tree at the Agricultural Experiment station --Afourer, Beni Mellal, 1983.

FIG. 2: Fruit of `Nadorcott` compared to those of `Murcott` -- BeniMellal 1992.

FIG. 3: Leaves and flowers of `Nadorcott`.

FIG. 4: Details of the `Nadorcott` fruit: side, apex, base, cross andlongitudinal section of `Nadorcott` at Marrakech, December 1996.

FIG. 5: Fructification of `Nadorcott`.

FIG. 6: Typical rind color -- of `Nadorcott` at Marrakech, in midwinter.

FIG. 7: Color of the juice of `Nadorcott` at Marrakech, in mid winter.

FIG. 8: Young orchard of `Nadorcott`, 2.5 years old at Marrakech,December 1996.

FIG. 9: The leaves of `Nadorcott`: upper and lower surfaces.

DETAILED DESCRIPTION

The following is a description of the `Nadorcott` variety as observedunder the growing conditions of Rabat, Beni Mellal and Marrakech. Thecolors except the color white referred to in the detailed descriptionare according to the Pantone Color Formula Guide. Identification of thecolor white is according to the Colour Chart of The Royal HorticulturalSociety.

Tree: The tree is very vigorous, taller than most mandarin cultivars andits parent, the `Murcott`. The young trees show an excellent rate ofgrowth and vigor. The shape of the tree is upright in habit for youngtrees. When bearing frits, the vigorous shoots drop giving the canopy aspreading shape.

The older trees have a rounded shape with ascending shoots on the top ofthe canopy and dropped on the edge.

Foliage: The leaves look like those of `Murcott` but less lanceolate,larger and not pointed. When ground, the leaves give an odor as that ofwillow leaf mandarin. The leaves are smooth on both sides.

Size.--Large for a mandarin group.

Length.--74 mm (with 10 mm for the petiole).

Width.--42 mm.

Shape.--Elliptic to oblong.

Color.--The upper surface is dark green (574C). The lower surface islighter green (377U).

Petiole.--10 mm. Wings are absent.

Marginal form.--The margin is slightly serrated.

Flowers:

Date of bloom.--Occurs at the same time as other citrus cultivars:beginning of March for the region of Marrakech, February for Rabat.

Number of petals.--4 to 5.

Number of sepals.--4 to 5.

Petal length.--7 mm.

Petal width.--3.5 mm.

Pedicel length.--5 to 6 mm.

Width of the closed flower.--7 to 11 mm.

Color of the petals.--White (155C).

Fruit:

Maturity.--Mid-season (begins by mid-December). The fruits are harvesteduntil the end of March.

Size.--Medium; the average fruit weight varies from 83 to 93 grams.

Form.--Oblate; both base and apex slightly depressed, the fruit shape isnot perfectly round; the average diameter varies from 60 to 68 mm, theheight of the fruit averages 46 to 49 mm. Those two parameters depend onthe growing conditions. The ratio of diameter/height of the fruit is1,24 to 1,38. The bigger fruits are short necked with prominent furrows.

Rind: The rind surface is smooth; orange red color (021U); this specificcoloration is reached by the beginning of Janurary in Marrakech; therind is thin: 2.5 to 3.5 mm with average of 2.8 mm; the adherence of therind to the flesh is medium but the fruit is at least as easy to peel asthe `Clementine` fruit; finely pitted, medium number of oil glands: 50per cm², oil glands globose and of medium size; the stylar scar isapparent and dry. It should be noted that the fruit on the sunny part ofthe tree might be rugose with a lighter orange color (137C); on theother hand, the shaded fruit has smooth rind with deep reddish orangecolor (1655C). In some cases, there is a pink color on the surface ofcontact between fruit. The fruit oil glands have refreshing effect anddistinct and very pleasant smell. When over mature, the big fruitbecomes puffy, but the flesh remains juicy.

Flesh; Irregular open axis, there are 8 to 13 segments per fruit with anaverage of 10; the segments are readily separated, the skin of thesegment is tender. The pulp is uniform deep orange (151C); mediumtexture; vesicles globose to obovoid and medium to large.

Juice: Fruit is very juicy even before maturity: 50%. The juice has anorange color (1495U), a strong and attractive aroma and an excellentflavor. The total soluble solids rate (E) is high: 110 to 150 dependingon the rootstock and the period of harvest, the acid content (A) is alsohigh at the beginning of the maturity (11 to 14 grams per liter). Theratio E/A reaches 6.5 during December in the Marrakech area.

Seed content: Under self-pollination conditions, fruits are seedless(average 0.2 to 0.5 seed/fruit).

Tree storage: Fruits hang well on the tree even when over mature.

Use: Mainly fresh eating mandarin.

Keeping quality: Excellent.

Shipping quality: Excellent.

Resistance to diseases: No particular disorder noticed.

I claim:
 1. A new and distinct variety of Mandarin Tangerine tree having the characteristics described and illustrated herein. 